Author/Authors :
J.K.Y، Law نويسنده Bioengineering Graduate Program, the Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Hong Kong , , C. K، Yeung نويسنده School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong (CUHK), Shatin, Hong Kong , , J، Frisch نويسنده Department of Informatics and Microsystem Technology, University of Applied Sciences Kaiserslautern, D-66482 Zweibrücken, Germany , , S، Knapp نويسنده Department of Informatics and Microsystem Technology, University of Applied Sciences Kaiserslautern, D-66482 Zweibrücken, Germany , , S، Ingebrandt نويسنده Department of Informatics and Microsystem Technology, University of Applied Sciences Kaiserslautern, D-66482 Zweibrücken, Germany , , J، Rudd نويسنده School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong (CUHK), Shatin, Hong Kong , , M، Chan نويسنده Bioengineering Graduate Program, the Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Hong Kong ,
Abstract :
Under hypoxia, sarcolemmal KATP (sarcKATP) and mitochondrial KATP (mitoKATP) channels exert cardioprotective effects via different mechanisms. In the present study, effects of potassium channel openers (KCOs) on electrophysiology (extracellular field potential, exFP) of the hypoxic heart were measured. During re-oxygenation, the mitoKATP channel opener diazoxide (DZX) reduced the hypoxic effect on the electrophysiology of atria without affecting the exFP duration. DZX also reduced the infarct size of hypoxic hearts (3.01 ± 1.62 %, n = 3). The myocardial cell area changes following KCOs pre-treatment further suggest that DZX-induced cardioprotection in isolated hearts was due to a preservation of cell volume via mitoKATP channel activation. On the other hand, the sarcKATP channel opener pinacidil did not show any significant cardioprotective effect on the heart following hypoxia. The present study demonstrates that the activation of mitoKATP channels may also be involved in cardioprotection following acute hypoxia.
